1. Field of the Invention
The present invention relates to a soft magnetic alloy and, more specifically, to a soft magnetic alloy used in electric transformers, pulse generators, compressions, electric chokes, energy-accumulating inductors, magnetic sensors, or the like, and a wireless power transmitting apparatus and wireless power receiving apparatus including the soft magnetic alloy.
2. Discussion of Related Art
A wireless power transmitting apparatus is connected to a power source, and includes a metal substrate, a soft magnetic sheet disposed on the metal substrate, and a transmission coil disposed on the soft magnetic sheet. In addition, a wireless power receiving apparatus is connected to a load, and includes a soft magnetic sheet and a reception coil disposed on the soft magnetic sheet.
Here, the soft magnetic sheet of the wireless power transmitting apparatus, and the soft magnetic sheet of the wireless power receiving apparatus may shield electromagnetic waves radiated from the transmission coil and electromagnetic waves received by the reception coil, respectively. Accordingly, an energy loss occurring between the wireless power transmitting apparatus and the wireless power receiving apparatus may be minimized, and a power transmitting and receiving efficiency may be improved.
Normally, Fe-based soft magnetic alloys may be used as shielding materials. The Fe-based soft magnetic alloys may be classified into, for example, an Fe—Si soft magnetic alloy, an amorphous soft magnetic alloy, and a nanocrystal soft magnetic alloy, etc. The Fe—Si soft magnetic alloy may be usable at a low frequency band of about 10 kHz since it has a low resistivity, although it has a high saturated magnetic flux density in the range of 1.5 T to 1.9 T. Accordingly, the Fe—Si soft magnetic alloy may not be applicable to a wireless charging system using a frequency band in the range of 110 to 250 kHz. The amorphous soft magnetic alloy or nanocrystal soft magnetic alloy including Fe, a ferromagnetic element, and a metalloid element may be used at a frequency band in the range of 110 to 250 kHz. However, since the soft magnetic alloy including Fe and a metalloid element has a low saturated magnetic flux density of 1.56 T or less, it is difficult to be thinned and manufacturing costs thereof may increase.